The game of tennis, and similar racket-based games such as racket ball and squash, have wide spread popularity around the world. When playing racket-based games, whether for recreation or professionally, it is important to have a racket with proper string tension.
Current devices for measuring string tension are inadequate in that none make a combined measurement of the racket string hardness and the string elasticity of the racket string tension, make a measurement racket string hardness and string elasticity simultaneously and independently of the size of the racket head and its string tension density, have a high measured value resolution and are insensitive with respect to side effects such as the influence of temperature and different conditions when playing, and permit self-adjustment of the device in the event of side effects.